Thiophene derivative polymer is an important kind of conductive polymers. They often have good electrochemical activity, environment stability and ease of processing. Here, 3-bromothiophene and 3-thiophenezoic acid as monomers, using chemical oxidation approach, the poly (3-thiophenezoic acid) (PTPA), the copolymer of 3-bromine thiophene (BTP) and 3-thiophenezoic acid (TPA) are synthesized in the media of chloroform or methanol. The structures of both polymers are characterized with FT IR, NMR and UV-vis. The results showed that the reactivity of TPA can be improved after alkalizing. The copolymer has strong absorption in the UV region. Its absorption band and intensity are higher than that of PTPA.